Rotary pump



G. R. FUNK ROTARY PUMP April 7, 1942.

Filed June 18,1941 2 Sheets-Sheet 1 67413 Fz/NK BY Z ATTO RNEYST INVENTOR April 7, 194-2. FUNK 2,279,136

- ROTARY PUMP Filed June 18., 1941 2 Sheets-Sheet 2 INVENTOR G/LASEQT E, FUNK 2M, MJMFM ATTOKN E Y5.

Patented Apr. 7, 1942 ROTARY PUMP Gilbert R. Funk, Waukesha, Wis., assignor to Waukesha Foundry Company, Waukesha, Wis., a corporation of Wisconsin Application June 18, 1941, Serial No. 398,550

Claims.

My invention relates to improvements in sanitary rotary pumps, with particular reference to devices for pumping Iiquiform foods and other materials requiring frequent separation and cleansing of the pump parts.

My objects are to eliminate rubbing contacts of relatively stationary and movable pump parts in all cavities occupied by the fluid that is being pumped-to facilitate a separate cleansing of the individual parts during intervals between pumping operations, and to avoid either liquid or mechanical erosion of parts exposed to liquid pressures.

A further object is to provide such a pump with a rotary seal which may be located within the pump body, exterior to space occupied by the liquid that is being pumped.

It is also my object to provide a pump assembly which can be taken apart and reassembled by inexperienced persons without the aid of tools, and with absolute factory predetermined precision in the positioning of the respective parts; to provide such a pump with rotary seal assemblies which will be automatically placed under tension while the pump pistons are being assembled in operative position; to provide a one-piece pump body which will be releasable from the supporting gear case by removal of a detachable cap and a set of pump pistons; to provide drainage facilitating clearance between the pump body and the gear case; and in general to provide a rotary pump peculiarly suited for use in the dairy and food industries.

More specific objects are to provide a rotary pump in which the shafts are wholly supported in gear case bearings, with short sturdy working end portions extending through a wall of the gear chamber into an associated pump chamher, and provided with balanced pistons revoluble in a lobed cavity along paths which intersect the front wall of the pump chamber, the pistons and the pump body being successively removable,

' leaving the working end portions of the'shafts exposed, the connecting bolts being also preferably left permanently associated with the gear case to be exposed by removal of said pump parts, and all of the removed parts being replaceable without the aid of tools and without danger of injury to the working 'parts by reason of acci dental release of any of the parts during a pump ing operation.

Further objects will be apparent from the description.

This application is a continuation in part of my former application, Serial No. 322,502, filed March 6, 1940.

In the drawings:

Figure 1 is a side elevation of a preferred embodiment of my improved pump, with parts broken away in vertical section.

Figure 2 is a front end elevation, with a portion of the pump chamber cap wall removed.

Figure 3 is a sectional view drawn to a plane indicated by the line 3--3 of Figure 1 and looking toward the gear chamber.

Figure 4 is a view drawn to the same plane and looking toward the pump chamber.

Figure 5 is a perspective view of the gear case with the pump chamber removed, and showing the working ends of the shafts and the connecting plates. v

Like parts are identified by the same reference characters throughout the several views.

In the preferred embodiment of my invention illustrated in the drawings, the driving shaft [0 and intergeared shaft ll may be permanently mounted in suitable bearings l2 in a gear casing l3. The working or piston carrying ends of the shafts Ill and I I extend through the front wall of the gear casing into a pump chamber in which they are otherwise unsupported.

The body or major portion of the pump chamber has an outer or peripheral portion l5 abutting the front wall of the gear casing, and the rear wall Id of the body is inset or recessed, as indicated at it. The rear wall I4 is provided with integral shaft receiving sleeves I1, having an internal diameter larger than the portions I8 of the shafts which they receive.

Where the shafts pass through the front wall of the gear casing they have annular flanges l9 encircled by oil seals 20, interposed between the bearings l2. Apertured disks of plates 2| in pressed fit relation to their respective shafts are loosely fitted to recesses in the front wall of the gear case and seat against the flanges l9. These plates may be aptly termed slinger ,plates, since they revolve with the shafts, and any oil from the gear case or milk from the pump chamber is deflected radially, thrown by centrifugal force into the cavity l6 between the two chambers, from which it is allowed to pass out at the bottom through the drainage aperture 38.

Near their front ends, the shafts are further reduced in diameter as indicated at 22 to receive the hub portions 23 of the pistons 24. The piston hubs 23 are keyed to the portions 22 of the shafts, and the extremities of the latter are still further reduced and threaded to receive nuts 25 which body of the pump chamber, each sleeve l'l being.

arcuately recessed at so in conformity with the circle traversed by the outer surfaces of the 'pistons on the opposing shaft.

The inner faces of the piston hubs 23 are in running fit relation to the front ends of the sleeve l1, and the rear ends of the sleeves are closed by thrust collars 32 which are threaded to the rearwardly projecting ends of the sleeves with their internal diameters substantially corresponding to those of the shaft portions l8. Sealing rings 33,34 and 35 encircle each shaft portion l and are held against the associated thrust collar 32 by a coiled compression spring 38, interposed between the sealing rings and the associated piston hubs 23. The rings 33 have reduced annular friction bearings upon the thrust collars I2 and normally rotate with their shafts. The ring 34 is preferably compressible 0n the shaft.

Any seepage escaping past the piston hubs and sealing rings will be delivered into the cavity It in the rear wall of the pump chamber and allowed to escape through the bottom opening 38. Therefore, although the sealing rings are located within the body of the pump, they are exterior to the chamber or cavity which receives the liquid that is being pumped, and for all practical purposes they are outside of the pump chamber.

' They are located within the body in order that the working end portions of the shafts may be of minimum length and projection beyond the gear chamber bearings and maximum resistance to vibration.

The pump chamber is composed of separable parts, viz., the body portion, which includes the back wall H, the outer wall l5, and the sleeves i1, and a cap wall 40 doweled to the body at 4|.

The body is also doweled to the gear casing at 42, and bolts 43, having heads permanently mounted in the gear casing, extend through the pump body and cap, whereby both the body and cap wall of the pump chamber may be clamped to and supported from the gear casing by these bolts and a set of clamping thumb nuts 44.

The clamping nuts 44, together with the nuts 25 which clamp the piston hubs in place, and the thrust collars 32 which receive the pressure of the clamping nuts 25 exerted through the compression springs 36 and the sealing rings, may all be adjusted in normal operating position without the aid of special tools, although special wrenches are preferably employed to secure the thrust collars 32 and nuts 25 in place. The thrust collars 32 are held against accidental rotation by a single locking block 46, held to the front wall of the gear casing by a screw 46a. As best shown in Figure 4, this locking block 40 hasflat faces which abut some of the flat faces 41 of each of the thrust collars 32, thus preventing those collars from turning during operation of the pump.

There is a possibility that the clamping nuts 25 might tend to work lose during operation of the pump, especially if carelessly adjusted to clamping position, or if adjusted by hand without the aid of tools. Ordinarily these nuts will remain in place, but during a prolonged pumping operation, if one of them should work loose and drop away from its associated shaft, it will be received in the recess 48 formed in the pump cap directly opposite the end of the shaft, and this recess is sufliciently large to allow the nut to drop away from the shaft end to a position in which it cannot damage the threaded end of the shaft.

The clearances now to be described are such that even if the nuts 25 should drop away the pistons and their hubs will be held in nearly their normal positions until the next cleansing and reassembling operations.

With the above described construction, clearances of less than .005 may be provided between the pistons and the walls of the pump cavity, and between the piston hubs and the ends of the sleeves i l on one side and the cap 40 on the other. without danger of wearing contacts, break-down of fat globules, or other damage to the liquids which are being pumped. Vibration being virtually eliminated, a clearance of .035 is permissible, and this running fit relationship of the parts is sufllciently close to enable the pump to develop pressures up to 300 pounds to the inch without material seepage into the sleeves which enclose the packing rings, and without material slippage past the pistons. Vibration and wear being substantially eliminated, the durability of the pump is greatly improved, and liquiform foods can be pumped without impairment.

I am aware of the fact that rotary pump shafts have heretofore been provided with paired pistons for the purposeof improving the continuity of delivery over that obtainable when each shaft is merely provided with a single piston. But I believe I am the first-to employ paired and balanced pistons in-combination with short, sturdy shaft ends which support the pistons in a socalled "outboard" position from bearings located wholly in the gear casing. By housing the sealin rings wholly within the pump chamber I make possible the use of such short, sturdy shafts as to virtually eliminate vibration if the paired pistons are properly balanced, and I am thus enabled to limit the clearance between movable and stationary parts to a tolerance ranging from .002" to .004", which precludes substantial seepage between the relatively movable parts.

I claim:

1. A sanitary rotary pumping mechanism for milk and other material containing fat globules or cellular constituents, comprising the combination of a gear casing provided with shaft supporting bearings, a pair of parallel shafts wholly supported by said bearings and having piston carrying working portions projecting through one wall of .le casing, connecting bolts permanently mounted in the gear case and projecting therefrom parallel. to the working portions of the shafts. a pump chamber body, apertured to receive said connecting bolts and projecting shaft portions. said body having housing sleeves axially enclosing the working portions of the shafts. and a'nnularly spaced therefrom, piston hubs detachably connected with the shaft ends in 0105- 1 ing relation to the front ends of the sleeves and each provided with a pair of balanced pistons revoluble about the respective sleeves. sealing rings interposedbetween the sleeves and shafts, and a detachable front wall for the pump chamher body free, from bearing contact with the shafts, hubs and pistons, said shafts being free from bearing contact with any-portion of the pump chamber.

2. A pumping mechanism as set forth in claim 1, in which the rear ends of the sleeves are provided with removable thrust collars and the packing rings are held under resilient pressure in thrust relation to the hubs and thrust collars, the cap wall, piston hubs with their associated pistons and the pump body being successively removable from the working ends of the shafts, and the thrust collars and packing rings being also separable from the removed pump body.

3. In a pumping mechanism of the described class, a set of permanently mounted parallel shafts, each having one end portion provided with suitable bearings and the other end portion free from bearing contacts and adapted to serve as piston carrying working portions, a pump chamber formed inseparable parts independently supported to enclose the working end portions of the shafts and provided with a lobed piston receivjng cavity in which the working end portions of the shafts terminate, and pistons detachably connected with said working portions and revoluble in the respective lobes, said working portions of the shafts and their pistons being free from bearing contact within the pump chamber and said pump chamber and the pistons being removable from the working portions of the shafts and separable for cleansing purposes after each pumping operation.

4. A rotary pumping mechanism for liquiform foods, having, in combination, a gear case provided with shaft supporting bearings, a pair of parallel shafts intergeared to revolve in opposite directions and wholly supported in said bearings with free working end portions projecting from the gear case, a pump chamber body having inlet and outlet ports and provided with sleeves concentric with working portions of the shafts and annularly spaced therefrom, said body having a lobed piston receiving cavity, with the walls of each lobe concentric with one of the sleeves, piston hubs d-etachably connected With the free ends of the shafts in running fit relation to the ends of the sleeves and each provided with a pair of balanced pistons revoluble in one of the lobes in paths which intersect those of the other set of pistons, and a detachable cap wall for the pump chamber spaced from the shaft ends and normally closing the piston receiving lobes,

5. A sanitary rotary pumping mechanism, having in combination a gear casing provided with shaft supporting bearings, a pair of parallel shafts wholly supported by said bearings and having piston carrying working portions projecting through one wall of the casing, a pump chamber having a body detachably connected with said casing Wall and having sleeve housings concentric to the associated portions of the shafts and annularly spaced therefrom throughout their length, removable thrust collars normally closing the rear ends of the housings, rotaryseals carried by the shafts within the sleeves in thrust relation to said collars, a retaining block normally secured to said Wall of the gear casing between the thrust collars and adapted --to hold them against rotation, piston carrying hubs secured .to the front ends of the working portions of the shafts and each provided with a set of balanced pistons rotatable within the pump chamber body, clamping nuts normally holding said hubs in position, and a removable front wall for the pump chamber body supported thereby out of contact with the shaft ends and piston hubs, said hubs and pistons being in running fit relation to the interior surfaces of the pump chamber, and the working portions of the shafts being sufliciently short and sturdy to normally hold thgpiston hubs and pistons out of bearing contact with the walls of the pump chamber, with a clearance insufficient to permit material loss of efllciency by flow of liquid from the high pressure to the low pressure sides of the pistons.

6. A pumping mechanism as set forth in claim 5, in which the cap wall of the pump chamber is provided with recesses, each of suflicient depth to allow an unthreaded clamping nut to drop therein out of contact with the shaft ends if accidentally separated from the shafts during a pumping operation.

7. In a rotary pump of the described class, the combination of a gearchamber, of a set of parallel shafts having supporting bearings wholly mounted in the gear chamber and having working ends projecting through apertures in one wall of said chamber, each said shaft having an annular flange and concentric oil sealing rings closing the aperture in said wall, washer-shaped slinger plates each in pressed fit relation to one of the shafts in a'position to intercept fluid tending to follow the shaft in either direction from or into the gear chamber and to deliver such fluid centrifugally, a pump chamber enclosing the working ends of the shafts and having its inner ing end portions projecting from the casing;

wall recessed to receive liquid d scharged from from the slinger plates, and pistons carriedby,

the shafts and adapted to revolve in intersecting paths within the pump chamber, said shafts and pistons being free from hearing contact within the pump chamber.

8. In a rotary pump, the combination of a piston carrying shaft, a sleeve of greater internal diameter than the shaft and through which the shaft passes with continuous annular clearance between the shaft and sleeve, a piston hub closing one end of the sleeve. a collar closing the other end thereof, and packing rings between the shaft-and sleeve in thrust relation to the pistcnhub and collar, said pistcnhub having thereto.

9. In a sanitary rotary pump for liquiform foods, the combination of ashaft supporting gear casing provided with parallel shafts having worka pump chamber having separable walls enclosing said end portions, means for detachably clamping said walls to the gear casing, and pistons detachably secured to the ends of said shaft portions and supported thereby in running fit relation to the walls of the chamber, with a tolerance of less than .005 of an inch, the pump chamber being without bearings for the shafts and pistons and said shafts being wholly supported from said gear casing and sufliciently sturdy, and the rotary parts sufliciently balanced, to substantially avoid vibratory or wearing contacts of surfaces exposed to the pumped material.

10. A rotary pump having interacting segmen tal pistons wholly supported from a gear case by intergeared parallel shafts revoluble in opposite directions, in combination with a removable pump body having a back-wall supported by the gear case, said body having, an open piston receiving lobed cavity in front of the back wall, and said back wall being apertured to allow the respective shafts to extend across the cavity at the axis of each lobe, sleeves concentric to .the respective shafts and supported from the back wall with the pistons in running fit relation to the outer surfaces of the sleeves and the opposing lobe sur-' and hubs and with the front faces of the pistons cap. said sleevesin running fit relation to the being spaced from the respective shafts and provided with interposed relatively fixed and rotary sealing devices adapted to obstruct the flow of liquid through the the back wall.

11. In a rotary pumping mechanism, the combination of a gear chamber and an associated removable pump chamber, a set of parallel shafts mounted in supporting bearings located wholly in the gear chamber, said shafts having free end portions projecting into the pump chamber, pistons splined to the free end portions of the shafts, and manually removable clamping nuts for securing the pistons to the shafts, said pump chamber being formed in cap and body portions, having, in common, manually releasable connections with the gear case.

12. A rotary pump, comprising the combination of a gear chamber, a set of intergeared parallel shafts having their bearings mounted in the gear chamber, with otherwise unsupported working end portions extending through one wall of the chamber, a pump chamber having a manually removable front wall, and a rear wall normally supported by said wall of the gear chamber and recessed to permit drainage, shaft receiving sleeves extending forwardly from said rear wall into the pump chamber. removable packings normally interposed between the sleeves and the shafts, piston having hubs manually removable from the free ends of the shafts and normally supported thereby in running fit relationship to the sleeves and the walls of the pump chamber, said hubs normally closing the front ends of the sleeves, thrust collars normally closing the rear ends of the sleeves, manually removable nuts for holding the piston hubs to the shafts, and other manually removable nuts for holding the pump chamber cap and rear wall to the gear case-all parts of the pump being removable by removal of said cap nuts and piston clamping nuts, whereby all of the parts may be separately cleansed.

13. In a rotary pumping mechanism of the described typ the combination of a gear chamber, a set of parallel shafts permanently mounted therein, with free end portions projecting from the gear chamber and provided with manually detachable pistons on their extremities, a pump chamber formed in manually removable revoiuble about the free end and separable parts, said supported from the gear chamber and provided with shaft receiving sleeves of greater internal diameter than the shafts, and packing devices housed between the shafts and sleeves-the pistons and said projecting ends of the shafts bein housed within the pump chamber and supp rted by the gear ing contacts with the walls thereof.

14. In a rotary pumping mechanism, the combination of a gear chamber, a set of intergeared parallel shafts wholly supported in gear chamber mountings and having working end portions projecting through one wall of said chamber, a pump chamber formed in separable parts and manually connectible with the gear chamber to be supported thereby in housing relation to the working ends of the shafts, said shaft portions having reduced front ends adapted to receive piston hubs in splined relation thereto, and extremities threaded to receive clamping nuts adapted to fix the position of the piston hubs on the shafts, and pistons supported from the respective hubs to revolve about the tersecting paths, said shafts, piston hubs and pistons being supported to revolve in running flt relationship to the fixed walls of the pump chamber and said walls and pistons being manually removable to expose the working ends of the shafts and permit separate cleansing of all parts of the pump after each pumping operation.

15. A sanitary rotary pumping mechanism for milk and other liquiform food material, comprising the combination of a pump body formed in manually separable parts and having an apertured wall provided with sleeves concentric to the respective apertures. each sleeve having a free end portion supported from said wall within the body, shaft bearings exterior to the body, shafts mounted in said bearings with free working end portions extending axially through said sleeves in spaced relation thereto, piston hubs each detachably secured to the front end of one of the shafts and provided with balanced pistons portion of the associated sleeve, thrust collars, concentric with the respective shafts and substantially closing the rear ends of the sleeves, and rotary sealing rings interposed between the shafts and sleeves in thrust relation to said collars and the piston hubs-the shafts, pistons and piston hubs being wholly supported from said shaft bearings, and all movable portions within the pump body being free from rubbing contact with any portion of the body.

GILBERT R. FUNK.

pump chamber being chamber mountings free from bearshafts in in- 

